Water displacing rust preventive compositions and process of coating a base therewith



Patented Aug. 4, 1953 TNT WATER DISPLACING RUST PREVENTIVE COMPOSITIONS AND PROCESS OF COATING A BASE THEREWITH William A. Zisman, Washington, D. C., and Hayward R. Baker, Mount Rainier, Md.

No Drawing. Application September 16, 1949, Serial No. 116,202

(Granted under Title 3% s. Code (1952 Claims.

sec.

This invention relates to water-displacing corrosion-inhibiting compositions.

The so-called water-displacing compositions heretofore known in the art have been at best, mere corrosion-preventative agents, since none has been capable of displacing a water film of any appreciable thickness from a surface to be treated. Of all of the commercially available products examined in connection with the research on this subject, the present inventors found none that would displace a Water layer as great as 2 mm. thick from a steel test-plate, and only one that would produce even the slightest displacement of a 1 mm. film of water from such a plate. Moreover, the commercial products studied were all found to include non-volatile components in excessive amounts ranging from 18% to 55%, leaving residual films upon the surfaces under treatment which were inordinately thick. Moreover, since none of these products was compatible with commercial types of electrical insulation, they are entirely unsuited for uses in which electrical equipment is encountered.

Now, by virtue of the present invention, a relatively high degree of water-displacement is achieved, non-volatile components are maintained at a very low value, film thickness is greatly reduced, and practically any type of material, including electrical insulation, can be treated with complete satisfaction.

The more important requirements of true water-displacing corrosion-inhibiting compositions include a high equilibrium spreading pressure to assure their complete distribution over the surface to be treated; they must displace the water in contact with such a surface; they should remain completely effective for extended storage periods; their major portions should evaporate rapidly; they should leave a relatively thin protective film on the surface under treatment; their flash points should be reasonably high; they should not be toxic; and they should not adversely affect the surface to be treated.

As set forth in a copending application Serial Number 781,108 filed October 21, 1947, now abandoned, of which this application is a continuation-in-part, when a true water-displacing corrosion-inhibiting composition is applied to a film of water covering a surface to be treated, the composition spreads very rapidly over the water film and by virtue of its solubility characteristics, penetrates the film, contacts the surface to be treated, and becomes adsorbed on the surface as an oriented monomolecular bydrophobic film covering the entire area. Inasmuch as the water-displacin component evaporates rather quickly, only the corrosion-inhibiting ingredient will remain to constitute a protective film.

Whereas a number of liquid polar compounds display many of the necessary characteristics, in that they possess high equilibrium spreading pressures, penetrate a relatively thick layer of water, and become adsorbed by underlying surfaces of various types to form thin hydrophobic films, these compounds alone have failed to provide a complete answer to the problem because they evaporate rapidly, failing to produce a lasting protective film on the surface under treatment. Exploration of many classes of compounds including alcohols, ethers, glycol-ethers, ketones, acetoacetates, lactates, carbonates and oxalates, has failed to indicate an individual compound possessing all of the characteristics required for a water-displacing corrosion-inhibiting composition suited for general application. An intensive study of the compounds of these classes in combination with compatible compounds of a complementary nature, has led to the discovery of highly satisfactory water-displacing corrosion-inhibiting compositions possessing all of the necessary requirements; It has been found that certain alcohols are eminently suited for use as the water-displacing component in conjunction with various corrosioninhibiting components which are miscible therewith in proportions of from 0.1% to less than 10.0% by weight, which are substantially nonvolatile, which are polar, which have boiling points exceeding 150 'C'.,' and which possess a water solubility not exceeding 3.0% by weight.

Aliphatic monohydric alcohols containing fewer than four carbon atoms to the molecule are substantially completely soluble in Water and are therefore unsuitable for the purposes contemplated; moreover, the low fiash points of these compounds (under F.) would render their use hazardous for many purposes. On the other hand, those aliphatic monohydric alcohols containing more than eight carbon atoms per molecule approach complete insolubility in water, a property which is inconsistent with the essential function of penetratin the water film to establish contact with the surface to be preserved. Thus, the aliphatic monohydric alcohols and mixtures thereof containing from 4 to 8 carbon atoms and a straight chain of at least 3 carbon atoms per molecule are those with which this invention is primarily concerned, and within this group,

those containing from 4 to 6 carbon atoms per molecule are particularly effective. More specifically, butanols and their mixtures, and pentanols and their mixtures, have displayed excellent properties as the water-displacing component.

It may be noted that these alcohols containing from 4 to 6 carbon atoms per molecule have equilibrium spreading pressures ranging from 38 to 50 dynes per cm., boiling points from 108 to 195 C., flash points from 115 to 165 F., and melting points from 108 to 40 (3., thus adapting them for use overa wide range of tempera tures Without the creation of undue fire hazards.

The preferred categories of alcohols have been found to be compatible and effective with a large and diversified number of corrosion-inhibitors of the polar type, which are substantially nonvolatile at temperatures below 150 C. and noncorrosive and a water solubility not exceeding 3 by weight. Such inhibitors include: oleic acid, phenyl undecylie acid, phenyl stearic acid, xylyl stearic acid, xenyl stearic acid, dodecyl phenyl stearic acid, naphthenic acid, sorbitan monooleate, mannitan monooleate, sorbitan dilaurate, sorbitan triricinoleate, diglycol laurate, diglycol ricinoleate, diethyleneglycol monolaurate, glyceryl monooleate, glyceryl dioleate, zinc phenyl undecanoate, zinc ethyl phenyl stearate, magnesium phenyl stearate, calcium xenyl stearate, sodium petroleum sulfonate, barium petroleum 'sulfonate, dodecyl ammonium laurate, cyclohexyl ammonium laurate, and dicyclohexyl ammonium laurate.

Inasmuch as the compositions must sometimes be stored over long periods of time without loss of stability, various antioxidants may be added in small quantities without adversely afiecting the required properties of the compositions. Antioxidants which have been employed advantageously for this purpose include: 2, G-ditertiarybutyl--methylphenol (1 21441); 2, l-dimethyl 6 tertiarybutylphenol (24M6B); n butylamminophenol combined with a small addition of butylphenylenediamine (UOP i); and di-secbutyl-p-phenylenediamine (UOP).

For applications in which high values of equilibrium spreadingpressures are not necessary to produce the required results, the cost of the material "can be reduced by the use of suitable diluents. It has been found that aliphatic hydrocarbons of the Stoddard types for example, such as Varsol No. 1, may be used for dilution of the polar solvent. Tests have shown that the addition of up to 50% of Varsol No. 1,'cumene, or isooctane, to butanol mixtures, reduces the equilibrium spreading pressure at 20 C. by only a small amount and in a substantially linear fashion. For example, the addition of 20% of any "of these thre diluents decreases the equilibrium spreading pressure of the butanol mixture by'only 25 dynes per cm. From these tests' 'it has been concluded that up to 50% dilution 'with such hydrocarbons is consistent with reasonably effective results, and even greater dilution with more polar liquids may be feasible, provided that the particular diluent selected is adequate from the standpoints of volatility and flash point, and more important, that it does not substantially reduce the water-displacing property of the composition.

It'is among the objects of the present invention to produce a water-displacing corrosion-inhibiting "composition comprising more than 90% by weight of an aliphatic monohydric alcohol or mixture of aliphatic monohydric alcohols containing from 4 to 8 carbon atoms and a straight chain of at least v3 carbon atoms per molecule; and miscible proportions of from 0.1% to less than 10% by weight of a polar-type rust inhibitor which is substantially non-volatile at temperatures below 150 C. and has a water solubility not exceeding 3% by weight. The preferred alco- 1101 or alcohol mixture will contain from 4 to 6 carbon atoms per molecule, particularly favorable results having been experienced with butanols and butanol mixtures having a boiling point between 100 and 120 C. and a flash point above F., and pentanols and pentanol mixtures having a boiling point between 112 and 1402C. anda flash point above F. Advantageous results have attended the inclusion of less than 1% by weight of an antioxidant, and diluents in -proportions not exceeding 50% of the weight of the composition have been employed in some cases. Among the .rust inhibitors producing desirable results, glyceryl oleates and 'dioleates have been highly satisfactory. A highly desirable characteristic of many of the compositions contemplated herein is their property of removing fingerprint acids from surfaces.

Specific aliphatic alcohols of the type mentioned which have been productive of goodresults, include 1 butanol, 1 pentanol, v3 methyl 1- butanol, 2-methyl-1-butanol, .B-pentanol and 2- ethyl-l-butanol.

The water-displacing corrosion-inhibiting compositions contemplated herein are very useful for treating apparatus and equipment after exposure to seawater or fresh water, and find immediate application in connection with marine salvage operations. A specific example indicating suitable procedural steps utilizing the compositions of the present invention is outlined as follows:

An Allis-Chalmers motor-generator set, comprising a 115 volt D. C. motor, a 1-kw.-115 volt A. C. generator, and a Cutler-Hammer controller for the .motor, was operated for forty-eight hours under a load of 1320 watts, during which a number of resistance values were observed. This equipment was then immersed in a tank of synthetic sea water for a period of one week, then removed and washed three times with city tap water. The equipment was then subjected to a compressed 'air blast for about ten minutes, and then sprayed by means of a conventional air spray gun with approximately one liter of a water-displacing corrosion-inhibiting composition'comprising a technical grade of n-butyl alcoholand 0.5% by weight of a concentrate of a commercial'mixture of glyceryl monooleate and glyceryl dioleate. Evaporation of the water and n-butyl alcohol was accelerated by applying a blast of air at a temperature of 200 F. using an electrical blower. This was continued for about thirty minutes, whereupon the various elemerits of the equipment were tested for electrical resistance and compared with the corresponding data obtained prior -to immersion.

The resistance readings of the motor components compared as follows:

Ohms Before Immersion Ohms After Immersion Shunt-field l 180.

Series field to irame 350.

Shunt field to frame infinite The resistance readings of the controller compared as follows:

After obtaining these readings, the motor was started at a low voltage which was gradually increased in order to warm the armature and fields and thereby expedite the evaporation of the water-butyl alcohol mixture. The voltage was increased to the normal rating in approximately one hour, and the set then ran under load for 48 hours, by which time the resistance values had increased to 90% of their original values before immersion.

' The residual polar, monomolecular, hydrophobic rust inhibiting film remained on the surfaces for at least six months, at which time an inspection showed no evidence of corrosion, and no damage to insulation.

Typical examples of compositions contemplated by the present invention are listed below, the proportions being based upon weight, and the Displacement value being the number of millimeters a film of water 1 mm. thick is displaced by the deposition of a 0.025 ml, drop of the composition on the surface of the water.

Example 1 l-pentanol percent 98.9 Glyceryl oleate do 1.0 Antioxidant (PX441) do 0.1 Displacement mm 44.5

Example 2 The composition of Example 1 diluted with 15% Varsol No. 1.

The composition of Example 3 diluted with 15% Varsol No, 1. 1

Displacement mm' 38.5 Example .5 3-methyl-1-butanol percent 98.9 Glyceryl oleate do 1.0 Antioxidant (PX441) do 0.1 Displacement mm 44.0

Example 6 The composition of Example 5 diluted with 15% Varsol No. 1.

Displacement mm 37.5

, Example 7 p 3-pentanol percent 98.9

Sodium petroleum sulfonate do 1.0

Antioxidant (24M6B) do 0.1

Displacement mm 45.0

Example 8 The composition of Example 7 diluted with 15% Varsol No. 1. v r r 6 Example 9 2-methyl-1-butanol percent v 98.9 Glyceryl oleate do 1.0 Antioxidant (24M6B) do 0.1 Displacement T mm 51.0

Example 10 The composition of Example 9 diluted with 15% Varsol No. 1."

Displacement mm 44.0

Example 11 The composition of Example 9 diluted with 30% Varsol No. 1.

Displacement mm 37.0

Example 12 2-ethyl-1-butanol percent 98.9

Glyceryl oleate do 1.0

Antioxidant (PX441) do 0.1

Displacement mm 50.5

Example 13 Thecomposition of Example 12 diluted with 15% Varsol No. 1."

The composition of Example 14 diluted with 15% .Varsol No. 1.

e composition of Example 16 diluted with 5% Varsol No 1," 1

Displacement Q. mm 39.0

Example 18 Y I l-butanol' p percent 50.0 2- ethyl-l -butanol do.... 48.9 Sodium petroleum sulfonate do 1;0 Antioxidant (PX441) do 1 0.1 Displacement mm 45.5

Example19 The composition of Example 18 diluted with 15% Varsol No.1. 1

Displacement mm 38.0

Example 20 l-butanol percentn 94.9 Glyceryl oleate do 5.0 Antioxidant (PX441) d0 0.1 Displacement mm 50.0

Example 21 The composition of Example 20 diluted with l 15% Varsol No. 1. Displacement 38.5 Displacement mm ape'z sse Example '22 T The. composition of Example diluted with Varsol No.1. l isplacement" 'mm 37.0

V t I V Example23 The compositioniof Example 20 diluted with 50% Varsol No. 1;"

. 'Thcomposition of Example 26 diluted with 15% fIVarsol No. 1'.' 7 Displacement in-1.1-1 mm 37.5

Inasmuch as there is a practical limit to the number of examples to be presented, and to the amount of detail to be recited, the foregoing material should be regarded in an illustrative sense, and not limiting beyond the scope of the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royaltie thereon or'therefor.

What is claimed is:

1. A water-displacing corrosion-inhibiting compositiongconsisting essentially of more than 90% by weight of at least one aliphatic monohydric alcohol having from 4 to 8 carbon atoms and a straight 'chain of at least 3- carbon atoms and. miscible proportions of from 0.1 to less than 10% by weight of a polar type rust inhibitor which has a water solubility not exceeding 3% by weight arid is substantially non-volatile at temperatures below 150 C. I I

2. A watcr displaci-ng corrosion-inhibiting com- "p'osition consisting essentially of more than 90% by weight of at least one aliphatic monohydric alcohol having from 4 to 6 carbon atoms and a Straight chain of at least 3 carbon atoms and miscible proportions of from 0.1 toless' than 10% by weight of a polar type rust inhibitor which has a water solubility not exceeding 3% by weight and is substantially non-volatile at temperatures be- .low 150 C.

'3. A water-displacing corrosion-mhibiting composition consisting essentially" of more than 90% by Weight'of at least one aliphatic monohy'dri'c alcohol having from 4 to 8 carbon atoms and a straight chain of at least 3 carbon atoms, miscible proportions of from 0.1 to less than 10% by weight of a polar type rust inhibitor which has a water solubility not exceeding 3% by weight is substantially non-volatile at temperatures I 8 below 150 qf aind less than 1% by weight of an antioxidant.

4. A water-displacing corrosion-inhibiting composition consisting; essentially of more than by weight or at least one aliphatic monohydric alcohol having from 4 to 8 carbon atoms and a straight chain of at least 3 carbon atoms, miscible proportions of from 0.1 to less than 10% by weight of a polar type rust inhibitor which has a water solubility not exceeding 3% by weight and is substantially non-volatile at temperatures below 150 Q, and a liquid hydrocarbon diluent of the Stoddard type in proportions not exceeding 50% of the weight of said composition. I

5. A water-displacing corrosion-inhibiting composition consisting essentially of more than 90% by weight of at least one aliphatic monohydric alcohol having from 4 to 8 carbon atoms and a straight chain of at least 3 carbon atoms, miscible proportions of from 0.1 toless than 10% by weight of a polar type rustinhibitor which has a water solubility not exceeding 3% by weight and is substantially non-volatile at temperatures below 150 C., less than 1% by weight of an antioxidant, and a liquid hydrocarbon diluent of the Stoddardtype in proportions not exceeding 50% of the weight of said composition. I I I 6. A water displacing corrosion inhibitin com-position consisting essentially of more than 90% by weight of mixed butanols having a boiling point between and C.- and' a flash point above 90 F. and miscible proportions of from 0.1 to less than 10% by weight of a polar type rust inhibitor which has a water solubility not exceeding 3% by weight and is substantially non-volatile at temperatures below 150 C.-

7. A water displacing corrosion inhibiting composition as set forth in claim 6 containing a liquid hydrocarbon diluent of the Stoddard type in proportions not exceeding 50% of the weight of said composition.

8. A water displacing corrosion inhibiting composition as set forth ifi claim 6 containing less than 1% by weight of an antioxidant.

9. A- water displacing corrosion inhibiting composition as set forth in claim 8 containing a liquid hydrocarbon diluent of the Stoddard type in proportions not exceeding 50% of the weight of said composition.

10. A water displacing corrosion inhibiting composition consisting essentially of more than 90% by weight of at least one aliphatic monohydric alcohol having from 4 to 8 carbon atoms and a straight chain of at least 3 carbon atoms and 0.1 to less than 10% by weight of a glyceryl oleate. I I

11. A water displacing corrosion inhibiting composition consistingessentially of more than 90% by weight of mixed butanols having a boiling point between 100 and 120 C. and a flash point above 90 F. and from 011' to less than 10% by weight or a glyceryl olea-te.

12. A water displacing corrosioninhibiting composition consisting essentially of more than 90% by weight of mixed pentanols having a boiling point between-1 1 2 and C. and a flash point above 100 F. and from 0.1 to less than 10% by weightof a glyceryl oleate. I

13. A method of displacingwater from andiniii-biting corrosion of a water-wet surface which comprises applying to said wet surface a composition comprising more than 90% by weight of at least one aliphatic menohydric alcohol having from 4 to 8 carbon atoms and a straightchain of at least 3 carbon atoms and miscible proportions 9 of from 0.1 to less than 10% by weight of a polar type rust inhibitor which has a water solubility not exceeding 3% by weight and is substantially non-volatile at temperatures below 150 C.

14. A method of displacing water from and inhibiting corrosion of a water-Wet surface which comprises applying to said wet surface a composition comprising more than 90% by weight of at least one aliphatic monohydric alcohol having from 4 to 6 carbon atoms and a straight chain of at least 3 carbon atoms and miscible proportions of from 0.1 to less than 10% by weight of a polar type rust inhibitor which has a Water solubility not exceeding 3% by weight and is substantially non-volatile at temperatures below 150 C.

15. A method of displacing water from and inhibiting corrosion of a Water-wet surface which comprises applying to said wet surface a composition comprising more than 90% by Weight of 1- 10 butanol and miscible proportions of from 0.1 to less than 10% by weight of a polar type rust inhibitor which has a Water solubility not exceeding 3 by weight and is substantially non-volatile at temperatures below 150 0.

WILLIAM A. ZISMAN.

HAYWARD R. BAKER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,339,200 Sowa Jan. 11. 1944 2,426,496 Farley Aug. 26, 1947 2,481,372 Von Fuchs et a1. Sept. 6, 1949 OTHER REFERENCES Handbook of Chemistry and Physics 28th Ed. 1944, Chemical Rubber Publ. (70., pages 802-803. 

1. A WATER-DISPLACING CORROSION-INHIBITING COMPOSITION CONSISTING ESSENTIALLY OF MORE THAN 90% BY WEIGHT OF AT LEAST ONE ALIPHATIC MONOHYDRIC ALCOHOL HAVING FROM 4 TO 8 CARBON ATOMS AND A STRAIGHT CHAIN OF AT LEAST 3 CARBON ATOMS AND MISCIBLE PROPORTIONS OF FROM 0.1 TO LESS THAN 10% BY WEIGHT OF A POLAR TYPE RUST INHIBITOR WHICH HAS A WATER SOLUBILITY NOT EXCEEDING 3% BY WEIGHT AND IS SUBSTANTIALLY NON-VOLATILE AT TEMPERATURES BELOW 150* C. 